Knowing whether to trust a software application prior to execution is a challenging task. There are endless viruses, bugs, worms, and other malicious software programs in existence today infecting computers on a daily basis. Most attacks are ones that could be prevented by an application screening program and/or the user's cooperation not to access an untrustworthy source of applications. There is no one type of virus protection software that is used to eliminate such an ongoing problem.
Trust level authorization, policy manager permissions, trusted sources, etc., are commonly used as guidelines to accept software applications prior to executing those applications on an end user's computer. Generally, these conventional trust guidelines employ a single source of trust establishment. However, there may be multiple different ways available to verify and confirm the legitimacy and integrity of an application source based on multiple policy models.